Diet rich in Omega-3s can fight breast cancer

A lifelong diet rich in omega-3 fatty acids can inhibit growth of breast cancer tumours by 30 per cent, according to new research from the University of Guelph.

Omega-3 fatty acids are found in oily fish like salmon and sardines, nuts, avocados and eggs. Omega-3 can also be taken as a supplement, like cod liver oil, but studies have shown that eating foods rich in omega-3s is more beneficial as the body better absorbs the nutrients.

The study, published recently in the Journal of Nutritional Biochemistry, is believed to be the first to provide unequivocal evidence that omega-3s reduce cancer risk.

"It's a significant finding," said David Ma, a professor in Guelph's Department of Human Health and Nutritional Sciences, and one of the study's authors.

"We show that lifelong exposure to omega-3s has a beneficial role in disease prevention - in this case, breast cancer prevention. What's important is that we have proven that omega-3s are the driving force and not something else."

Breast cancer remains the most common form of cancer in women worldwide and is the second leading cause of female cancer deaths.

Advocates have long believed diet may significantly help in preventing cancer. But epidemiological and experimental studies to back up such claims have been lacking, and human studies have been inconsistent, Ma said.

"There are inherent challenges in conducting and measuring diet in such studies, and it has hindered our ability to firmly establish linkages between dietary nutrients and cancer risk," he said.

"So we've used modern genetic tools to address a classic nutritional question."

For their study, the researchers created a novel transgenic mouse that both produces omega-3 fatty acids and develops aggressive mammary tumours. The team compared those animals to mice genetically engineered only to develop the same tumours.